Development of a system based on solid-state hydrogen storage materials has been actively undertaken in order to solve a current low volume storage density problem of a high-pressure gaseous hydrogen storage system.
However, a complex hydride based on a metal hydride, which is one type of the solid-state hydrogen storage materials, is reversible and has high storage capacity, but requires a high temperature environment of about 100° C. and continuous heat supply in order to release hydrogen. In other words, the metal hydride is excellent in reversibility of hydrogen release and storage reaction, but has a difficulty in practical usage because it is operated at a high temperature and needs a continuous heat supply for the hydrogen release. Further, development of such a solid-state hydrogen storage system that is operated at a high temperature is ongoing.
A hydrogen combustion device may be mounted, or a heat exchanger may be installed, in the solid-state hydrogen storage system to improve the supply of heat thereto. In this case, the heat exchanger may heat a storage vessel by using battery power. However, these solutions lead to a reduction in fuel efficiency due to energy loss.
Studies on ameliorating the problem by changing heat-exchanging fins, or types, sizes, positions, and the like of tubes inside a vessel, or a loading method of a hydrogen storage material, have been undertaken. However, these solutions lead to a reduction in weight storage capacity due to an increase in system weight.
Accordingly, improvements in minimizing the amount of heat needed to operate the solid-state hydrogen system and improving the weight storage capacity are required.